More workers are slowing down earlier, too: 15 percent of those 60 to 62 years old are partially retired. According to the University of Michigan report, in 1960, partial retirement among this younger group was “virtually non-existent.”

The study defines partial retirement as a job in which income doesn’t exceed 50 percent of the maximum annual earnings a person made in his lifetime.

In the analysis, researchers looked at lifetime earnings histories of white males between 1960 and 2010, categorizing the status of workers as full-time, partially retired or fully retired. (The study was restricted to white males as an attempt to control for changes in the racial and gender composition of the work force over these years.) Researchers also only considered people with at least five years of continuous earnings of more than $5,000 (in 1984 dollars), to exclude those with irregular working histories.

“It is becoming increasingly common for older workers to exit a career job prior to retirement and continue in a lower-paying ‘bridge’ job,” researchers wrote in a brief.

People between age 63 and 67 are especially sensitive to increases in the national unemployment rate, according to the report. For every 1 percent rise in unemployment, there’s a 1 percent drop in full employment for those between the ages of 55 and 75. And there’s as much as a 2 percent drop in full employment for those between 63 and 67.